HR BIO Chapter 3

Organic Compounds

Organic Compounds

Molecules primarily made of carbon and hydrogen, often containing other elements like oxygen, nitrogen, sulfur, and phosphorus.

Polymers

Large molecules made by linking together many smaller molecules called monomers.

Monomers

Small, repeating units that join together to form polymers.

Dehydration Reactions

Chemical reactions that link monomers together by removing a water molecule.

Hydrolysis Reactions

Chemical reactions that break polymers into monomers by adding a water molecule.

Carbohydrates

Organic compounds made up of carbon, hydrogen, and oxygen, typically in a 1:2:1 ratio. They serve as a major source of energy.

Lipids

Organic compounds that are hydrophobic (water-repelling), including fats, oils, and steroids. They store energy and make up cell membranes.

Proteins

Organic compounds made of amino acids that perform various functions like catalyzing reactions, providing structure, and regulating processes.

Nucleic Acids

Organic molecules that store and transmit genetic information. They include DNA and RNA.

Fatty Acids

Long hydrocarbon chains with a carboxyl group at one end. They are key components of lipids.

Amino Acids

Organic molecules that are the building blocks of proteins. They contain an amino group, a carboxyl group, and a unique side chain.

Nucleotides

The building blocks of nucleic acids, consisting of a sugar, a phosphate group, and a nitrogenous base.

Peptide Bonds

The covalent bonds that link amino acids together in proteins

Polypeptides

Chains of amino acids linked by peptide bonds, which fold into proteins.

Saccharides

Sugars or sugar-like substances, classified as monosaccharides, disaccharides, and polysaccharides.

Monosaccharides

Simple sugars that are the basic building blocks of carbohydrates (e.g., glucose, fructose).

Disaccharides

Sugars composed of two monosaccharides linked together (e.g., sucrose).

Polysaccharides

Complex carbohydrates made up of long chains of monosaccharide units (e.g., starch, cellulose).

Glucose

A monosaccharide and a primary energy source for cells.

Fructose

A monosaccharide found in fruits and honey.

Sucrose

A disaccharide composed of glucose and fructose, commonly known as table sugar.

Amylose

A type of polysaccharide found in starch, composed of long, unbranched chains of glucose.

Starch

• A polysaccharide made of glucose units, used by plants to store energy.

Cellulose

A polysaccharide that makes up the cell walls in plants, providing structural support.

Nitrogenous Bases

The components of nucleotides that include adenine (A), guanine (G), cytosine (C), thymine (T) for DNA, and uracil (U) for RNA.

Ribose

A sugar present in RNA nucleotides.

Deoxyribose

A sugar present in DNA nucleotides.

Steroids

A type of lipid with a characteristic four-ring structure, including hormones like testosterone and cholesterol.

Cholesterol

A type of steroid that is a key component of cell membranes and a precursor for other steroids.

Basic Structure of Proteins

Proteins are composed of one or more polypeptide chains, each made up of amino acids linked by peptide bonds.

Triglyceride

A type of lipid made of one glycerol molecule and three fatty acids.

Unsaturated Fats

Lipids with one or more double bonds in their fatty acid chains, which are usually liquid at room temperature.

Saturated Fats

Lipids with no double bonds in their fatty acid chains, which are usually solid at room temperature.

DNA (Deoxyribonucleic Acid)

The molecule that carries genetic information in cells, characterized by a double helix structure.

RNA (Ribonucleic Acid)

A nucleic acid involved in protein synthesis and gene expression, typically single-stranded.

Double Helix

The twisted ladder-like structure of DNA, consisting of two strands running in opposite directions.

Sugar-Phosphate Backbone

The repeating chain of sugar and phosphate groups that forms the structural framework of DNA and RNA.

Base Pairs

The pairs of nitrogenous bases that connect the two strands of DNA (A-T and G-C) and RNA (A-U and G-C).

A-T and G-C:

The specific pairing of nitrogenous bases in DNA, where adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C).

DNA=AGCT

The sequence of nitrogenous bases in DNA: adenine (A), guanine (G), cytosine (C), and thymine (T).

RNA=AGCU

The sequence of nitrogenous bases in RNA: adenine (A), guanine (G), cytosine (C), and uracil (U).

Purines

The nitrogenous bases adenine (A) and guanine (G) that have a double-ring structure.

Pyrimidines

The nitrogenous bases cytosine (C), uracil (U), and thymine (T) that have a single-ring structure.

Single Strand Nucleic Acids (RNA)

RNA molecules that consist of a single chain of nucleotides.

Double Strand Nucleic Acids (DNA)

DNA molecules with two complementary strands forming a double helix.

Anti-Parallel

The orientation of the two strands in a DNA double helix, running in opposite directions.

Denaturation of Protein

The process where proteins lose their three-dimensional structure due to external factors like heat or pH changes.

Enzymes

• Proteins that act as biological catalysts to speed up chemical reactions.

Functional Groups

Specific groupings of atoms within molecules that have distinct chemical properties and reactivities. Examples include:

Hydroxyl

–OH group.

Carbonyl

C=O group.

Carboxyl

–COOH group.

Methyl

–CH₃ group.

Amine

• –NH₂ group

Sulfhydryl

–SH group.

Phosphate

–PO₄ group.